1. Field of the Invention
The present invention relates to a fluidized bed heat exchange apparatus of a flue gas heat recovery type for producing a high temperature water, and more particularly, to a fluidized bed heat exchange apparatus which recovers a waste heat of a flue gas containing a large amount of a water vapor emitted from a combustion apparatus and, in order to produce a high temperature water, forms a water fluidized bed and a heat medium fluidized bed in a multi-layer to first raise a temperature of a supply water of a low temperature in an upper water fluidized bed and secondly produce a water of a high temperature equal to or higher than 80° C. in a lower heat medium fluidized bed.
2. Description of the Related Art
Typically, a heat exchanger is installed to recover a waste heat from a flue gas of a high temperature emitted from a combustion furnace or a combustion apparatus installed at various industry sites.
However, in a general heat exchanger provided with a high temperature flue gas and a direct heat transfer tube for heat exchange, a contaminant material and a corrosive gas component contained within the flue gas are accumulated on a surface of the heat transfer tube of the heat exchanger, thereby reducing heat transfer efficiency and, in a severe case, a fuel passage of the flue gas may be blocked, and further, a low temperature corrosion phenomenon of a surface material of the heat transfer tube may occur due to a contaminant material adhered to the surface of the heat transfer tube.
In order to solve the above problem of the conventional heat exchanger, a water fluidized bed heat exchanger is proposed. The water fluidized bed heat exchanger efficiently recovers a latent heat of a water vapor gas contained in the high temperature flue gas through the heat transfer tube while the flue gas which rises through a perforated plate fluidizes a water to exchange a heat with the heat transfer tube, thereby preventing lowering of the heat transfer efficiency of the heat transfer tube due to the corrosive flue gas or the low temperature corrosion phenomena due to adhesion of the contaminant material.
Despite the above advantages, the conventional water fluidized bed heat exchanger has a structural problem in that, when producing a hot water by recovering the waste heat, a temperature of a supply water cannot be raised more than about 55° C. which is a saturation temperature of a wet air in a water fluidized bed in which the high temperature flue gas and the water are fluidized such that the conventional water fluidized bed heat exchanger has disadvantages in that improving a heating efficiency of the combustion apparatus by the water fluidized bed heat exchanger is limited and applicability of the hot water is limited due to its temperature equal to or below the saturation temperature, thereby rendering it difficult to apply the water fluidized bed heat exchanger.